burst (bûrst) v. burst, burst·ing, bursts v.intr. 1. a. To come open or fly apart suddenly or violently, especially from internal pressure. b. To explode. 2. To be or seem to be full to the point of breaking open: The sacks were bursting with grain. 3. To emerge, come forth, or arrive suddenly: burst out of the door. 4. To come apart or seem to come ...